Filling device for electric storage batteries



April 15, 1952 J. RULE 2,592,743

FILLING DEVICE FOR ELECTRIC STORAGE BATTERIES Filed Jan. 9, 19 50 men/12m file Z Patented Apr. 15, 1952 FILLING DEVICE FOR ELECTRIC STORAGE BATTERIES John Rule, Birmingham, England, assignor to Joseph Lucas Limited, Birmingham, England Application January 9, 1950, Serial No. 137,510 In Great Britain January 24, 1949 1 Claim.

This invention has for its object to provide an improved filling device through which water or electrolyte can be poured into an electric storage battery, the device being of the kind adapted to determine automatically the upper level of the liquid.

The accompanying drawing is a sectional elevation illustrating one mode of carrying the invention into effect.

Referring to the drawing, there is provided a hollow cylindrical neck a for receiving the liquid to be poured into the battery case. The neck may be formed integrally with the top b of the case, or it may be screwed into a hole in the top. In the lower part of the neck is placed a screen which is perforated by a number of small holes d through which the liquid can readily pass. The screen is a piston-like fitting which normally rests on a shoulder e in the lower part of the neck. Through the neck extends a venting tube of convenient diameter. The lower part of the tube reaches to the position corresponding to the desired level 9 of the liquid, and the upper part reaches to about the upper end of the neck.

Also a removable cover cap 72. is provided for closing the neck after filling.

The arrangement is such that liquid poured into the neck passes through the screen into the case, and displaced air is vented through the tube. When the liquid reaches the desired level it seals the lower end of the tube and by preventing further escape of air, prevents continued inflow of the liquid, the holes in the screen being sufiiciently small in size to be sealed by the liquid in the upper part of the neck when air can no longer escape through the venting tube.

The cessation of flow through the screen indicates that suflicient liquid has passed into the battery. Any liquid remaining in the neck above the screen, later drains into the battery when the latter is put on charge, as the increased gas 2 pressure thereby created in the case by electrolytic action raises the screen slightly and so lifts the lower end of the tube clear of the liquid. Gas can then escape through the tube and the residual liquid in the neck will then pass into the case.

By this invention the automatic determination of the upper level of the liquid is efiected in a very simple and convenient manner.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

A filling device for an electric storage battery, comprising in combination a filling neck, a screen of piston-like form slidable in the neck and formed with perforations through which liquid can flow, and a venting tube which is rigid with the screen and extends through the neck, and which is scalable at its lower end by the battery liquid upon the latter reaching a desired level, the perforations in the screen being sufficiently small in size to be sealed by liquid in the upper part of the neck when air can no longer escape through the venting tube, and the lower end of the neck being provided with an internal shoulder on which the screen is supported, but from which the screen can be raised by gas pressure in the battery to lift the venting tube and thereby permit any liquid remaining in the neck after a filling operation to drain through the per forations in the screen.

JOHN RULE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,907,911 Wallace May 9, 1933 2,457,322 Sandusky Dec. 28, 1948 

